Power recovery from quench and dilution vapor streams

ABSTRACT

A process for reducing pressure of a vapor stream used for reducing a temperature or pressure in a reactor. A pressure of a vapor stream is reduced with a turbine to provide a lower pressure vapor stream. The vapor stream rotates a turbine wheel within the turbine. The turbine wheel is configured to transmit rotational movement to an electrical generator. Thus, electricity is generated with the turbine. The lower pressure vapor stream is injected into a reactor and reduces a temperature in the reactor or reduces a partial pressure of a hydrocarbon vapor in the reactor.

FIELD OF THE INVENTION

This invention relates generally to vapor streams that are used in achemical processing or refining plant as a dilution fluid or a quenchfluid, and more particularly to processes wherein such vapor streamspass through a turbine to lower a pressure of the vapor stream andrecover energy from the pressure reduction.

BACKGROUND OF THE INVENTION

Chemical refining and processing methods frequently utilize diluent orquench fluids which added to help promote reaction(s) and/or controltemperature(s). Exemplary reactors that utilize these types of vaporstreams include petroleum refining fluidized catalytic cracking “FCC”reactors and hydroprocessing reactors. In reactors, the lowesttemperature of the diluent or quench vapor streams is occasionallylimited by the dew point of the vapor stream.

In an FCC reactor, steam is added to the transport reactor to transportcatalyst, as a working fluid for feed atomization and distribution, as astripping media to remove hydrocarbons from the catalyst prior toregeneration and to reduce the partial pressure of the lower molecularweight products thereby relieving equilibrium for cracking and promotinghigher conversion. Steam is used commonly for dilution in processoperations often to reduce the partial pressure of hydrocarbon topromote vaporization or forward reaction in mole generating reactions asin FCC. The use of steam is to provide a gaseous material that is easilycondensed and removed after its use. Many times, in the case of FCC, itis advantageous to have the steam as close to dew point as possiblesince the added energy is detrimental to the performance of the unit.The flow of hot catalyst added to the reactor is limited by maximumreactor temperatures promoting thermal cracking. Due to the usually highpressure drop from steam supply to the reactor riser, the steam enterswith a large amount of superheat unnecessarily producing a reactortemperature higher than what might be possible with a steam source withless superheat. This limits the hot catalyst circulation rate and tendsto give more unwanted thermal cracking versus catalytic cracking.

In a hydroprocessing reactor, the catalyst beds are often separated intomultiple beds due to the highly exothermic nature of hydroprocessing andthe need to quench the reactions and control the temperature. Betweenthe different reactor beds, a relatively low temperature (compared tothe process) hydrogen-containing vapor stream is added to quench thereactor temperature before the process fluid enters the next bedcatalyst. The use of the hydrogen-containing vapor stream requiresenergy as the quench stream is compressed. The hydroprocessing unitthroughput is often limited by flow of quench hydrogen to keep thereactor catalyst bed temperatures in a safe range.

In either conventional hydroprocessing or FCC reactors, the quench ordilution streams often passes through a control valve to control theflow of these vapor streams. While these conventional systems arepresumably effective for their intended purposes, the control valvesresult in a loss of mechanical energy. Specifically, since the energyremoved, via the pressure reduction, is dissipated without recovery bythe control valve, the energy is lost. Additionally, because the energyremoved often is a result of energy added to the system, the lost energycan represent a higher operating cost. This lost energy results inminimal temperature reduction versus the pressure reduction via anadiabatic pressure reduction across the control valve.

Therefore, there is a need for an effective and efficient device andprocess for recovery of this lost energy associated with such quench ordilution vapor streams in addition to a method to shift more of theenergy reduction to temperature reduction versus pressure reduction.

SUMMARY OF THE INVENTION

The present invention provides devices and processes that overcomes oneor more shortcomings associated with the prior art.

Specifically, according to the present invention, the control valve isreplaced with a turbine. By using a turbine, instead of control valve,the same or more energy removal to lower the pressure is achieved with agreater reduction in temperature following a more isentropic processthan with a control valve. A turbine in the quench or dilution streamchanges the reduction of pressure from an adiabatic operation (valvewith hot outlet temperature) to an isentropic operation where energy isextracted in the way of work on a shaft thereby producing a lowertemperature output while optionally generating power from the pressurelet down. Alternatively, the energy could be dissipated by a brake orother device in case the electricity recovery is not valued highlyversus the process improvement.

In the case of an FCC unit, having a dilution stream nearer its dewpoint will reduce the riser heat input allowing more heat to be added byincreased catalyst circulation and providing more selective cracking todesired LPG and naphtha components. In the case of a hydroprocessingreactor, less hydrogen will be required in the quench vapor streams,resulting in lower energy use in the recycle gas compressor, and/orallowing more hydrogen to be injected into the inlet of thereactor—promoting longer first bed catalyst life and higherhydrogenation in each bed but the last. At fixed hydrogen flow, thecooler hydrogen allows more hydrocarbon charge to the reactor as more ofthe heat of reaction is cooled with the same flow of now coolerhydrogen. Additionally, in addition to the foregoing benefits, theturbines convert the removed energy into electrical energy to beutilized elsewhere. Thus, the turbines provide an additional advantageover the control valves currently used with the dilution and quenchstreams.

Therefore, in at least one aspect, the present invention may becharacterized, as providing a process for reducing pressure of a vaporstream used for reducing a temperature, a heat load, or a hydrocarbonpartial pressure in a reactor by: reducing a pressure of a vapor streamwith a turbine to provide a lower pressure vapor stream; rotating aturbine wheel within the turbine; injecting the lower pressure vaporstream into a reactor in order to reduce a temperature or total heatinjection to the reactor or reduce a partial pressure of a hydrocarbonvapor in the reactor.

In another aspect, the present invention may be characterized, asproviding a process for reducing pressure of a vapor stream used foradjusting a partial pressure of a hydrocarbon vapor by: providing avapor stream comprising steam; passing the vapor stream through aturbine, the turbine comprising a turbine wheel within the turbine, theturbine wheel optionally configured to transmit rotational movement toan electrical generator; recovering a reduced pressure vapor stream fromthe turbine; and, reducing a partial pressure of a hydrocarbon vapor bymixing the reduced pressure vapor stream with the hydrocarbon vapor.

Further, in yet another aspect, the present invention may becharacterized, as providing a process for reducing pressure of a vaporstream used as a quench stream by: providing a vapor stream comprisinghydrogen; passing the vapor stream through a turbine, the turbinecomprising a turbine wheel within the turbine, the turbine wheeloptionally configured to transmit rotational movement to an electricalgenerator; recovering a reduced pressure vapor stream from the turbine;and, controlling a temperature within a reactor with the reducedpressure vapor stream from the turbine.

Additional aspects, embodiments, and details of the invention, all ofwhich may be combinable in any manner, are set forth in the followingdetailed description of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

One or more exemplary embodiments of the present invention will bedescribed below in conjunction with the following drawing figures inwhich:

FIG. 1 shows an FCC reactor used in accordance with one or moreembodiments of the present invention;

FIG. 2 shows a schematic drawing of a turbine according to one or moreaspects of the present invention; and,

FIG. 3 shows a hydroprocessing reactor used in accordance with one ormore embodiments of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

As mentioned above, the present utilizes one or more turbines to reducethe pressure and temperature through a nearly isentropic means andoptionally recover energy from a quench or dilution vapor stream in achemical processing unit. The optionally recovered energy, in the formof electrical energy, is, for example, used elsewhere in the processingunit. It is contemplated that power recovery turbines are installed onthese high-power let downs of hydrogen and steam into the reactorsthereby generating value from the energy recovered in addition toincreasing reactor conversion or throughput and reducing specificproduct energy intensity by allowing a lower hydrogen circulation rate,higher feed rate (throughput), or increased conversion.

With these general principles in mind, one or more embodiments of thepresent invention will be described with the understanding that thefollowing description is not intended to be limiting.

Turning to FIG. 1, in various aspects of the present invention, theturbine is used in a dilution stream associated with an FCC unit 10. Thedescription of this invention in the context of the specific FCC unit 10shown is not meant to limit the present invention to the detailsdisclosed therein.

The FCC unit 10 shown in FIG. 1 includes, generally, a separator vessel12, a regenerator 14, and a vertical riser 16. The FCC unit 10circulates catalyst and contacts feed in the manner hereinafterdescribed.

The catalyst comprises any of the well-known catalysts that are used inthe art of fluidized catalytic cracking, such as an active amorphousclay-type catalyst and/or a high activity, crystalline molecular sieve.Molecular sieve catalysts are preferred over amorphous catalysts becauseof their much-improved selectivity to desired products. Zeolites are themost commonly used molecular sieves in FCC processes. Preferably, thefirst catalyst comprises a large pore zeolite, such as an Y-typezeolite, an active alumina material, a binder material, comprisingeither silica or alumina and an inert filler such as kaolin. A catalystadditive may comprise a medium or smaller pore zeolite catalystexemplified by ZSM-5, ZSM-11, ZSM-12, ZSM-23, ZSM-35, ZSM-38, ZSM-48,and other similar materials.

FCC feedstocks include conventional FCC feeds and higher boiling orresidual feeds. The most common of the conventional feeds is a vacuumgas oil which is typically a hydrocarbon material having a boiling rangeof from 343° to 552° C. (650° to 1025° F.) and is prepared by vacuumfractionation of atmospheric residue. Heavy or residual feeds, i.e.,boiling above 499° C. (930° F.), are also suitable.

Looking then at FIG. 1, the riser 16 provides a conversion zone forcracking of hydrocarbons in the feedstock. The residence time for thefeed in contact with the catalyst in the riser 16 may be less than orequal to 3 seconds. Any residence time of less than or equal to 3seconds may be preferred depending on the desired product distribution.The shorter residence time assures that the desired products onceobtained do not convert to undesirable products. Notwithstanding theforegoing, different residence times may be utilized as will beappreciated by those of ordinary skill in the art.

The feedstock is introduced into the riser 16 by one or moredistributors or nozzles 19 between an inlet 18 to the riser 16 andsubstantially upstream from an outlet 20. Volumetric expansion resultingfrom the rapid vaporization of the feedstock as it enters the riser 16further decreases the density of the catalyst within the riser totypically less than 160 kg/m³ (10 lb/ft³). Before contacting thecatalyst, the feedstock will ordinarily have a temperature in a range offrom 149° to 316° C. (300° to 600° F.). Additional amounts of feedstockmay be added downstream of the initial feed point of the distributors19.

The blended catalyst and reacted feed vapors are then discharged fromthe top of riser 16 through the outlet 20 and separated into a crackedproduct vapor stream including olefins and a collection of catalystparticles covered with substantial quantities of coke and generallyreferred to as “coked catalyst.” In an effort to minimize the contacttime of the feedstock and the catalyst which may promote furtherconversion of desired products to undesirable other products, anyarrangement of separators to remove coked catalyst from the productstream quickly is used.

In particular, a swirl arm arrangement 22, provided at the end of riser16 can further enhance initial catalyst and cracked hydrocarbonseparation by imparting a tangential velocity to the exiting catalystand cracked product vapor stream mixture. Such swirl arm arrangements 22are more fully described in U.S. Pat. No. 4,397,738. The swirl armarrangement 22 is located in an upper portion of a chamber 24, and astripping zone 26 is situated in the lower portion of the chamber 24.Catalyst separated by the swirl arm arrangement 22 drops down into thestripping zone 26 (discussed below). The cracked product vapor streamcomprising cracked hydrocarbons including light olefins and somecatalyst pass, via conduit 28, to cyclones 30. The cyclones 30 removeremaining catalyst particles from the product vapor stream to reduceparticle concentrations to very low levels. The product vapor streamthen exits the top of the separating vessel 12 through an outlet 32.Catalyst separated by the cyclones 32 return to separating vessel 12through dipleg conduits 34 into dense bed 36 where it will enter thestripping zone 26 through openings 38.

The stripping zone 26 removes adsorbed hydrocarbons from the surface ofcatalyst by counter-current contact with steam. The steam entersstripping zone 26 through line 40. Any hydrocarbons removed in thestripping some 26 will flow upwards as described above. The catalystwill drop to a catalyst bed 42 at the bottom of the chamber 24.

Some catalyst from the catalyst bed 42 may be recycled to the riser 16without first undergoing regeneration. A second portion of the catalystfrom the catalyst bed 42 is regenerated in the regenerator 14 before itis returned to the riser 16. The second portion of the of the catalystfrom the catalyst bed 42 is transported to the regenerator 14 through acoked catalyst conduit 46 at a rate regulated by control valve 48 forthe removal of coke.

On the regeneration side of the process, coked catalyst transferred tothe regenerator 14 via the coked catalyst conduit 46 undergoes thetypical combustion of coke from the surface of the catalyst particles bycontact with an oxygen-containing gas. The oxygen-containing gas entersthe bottom of regenerator 14 via an inlet 48 and passes through a densefluidizing bed of catalyst (not shown). Flue gas consisting primarily ofcarbon dioxide and perhaps containing carbon monoxide passes upwardlyfrom the dense bed into a dilute phase of regenerator 14. A separator,such as cyclones 50 or other means, remove entrained catalyst particlesfrom the rising flue gas before the flue gas exits the regenerator 14through an outlet 52. The combustion of coke from the catalyst particlesraises the temperatures of the catalyst which is withdrawn from theregenerator 14 in a regenerator standpipe 54.

The regenerator standpipe 54 passes regenerated catalyst from theregenerator 14 into a blending zone 57 at a rate regulated by controlvalve 56. The flow rate of this catalyst is typically maximized toprovide the highest conversion selective to desired gasoline and LPGproducts at the highest production rate. This catalyst provides most ofthe heat for the reactor and the flow is limited by the temperature inthe riser. Therefore, anything that reduces the heat input to the riserallows for higher catalyst circulation rates, and higher conversions orhigher feed rates.

In the blending zone 57, the regenerated catalyst is blended withcatalyst directly from the catalyst bed 42. A fluidizing gas is passedinto the blending vessel 56 from a conduit 58. The fluidizing gascontacts the catalyst and maintains the catalyst in a fluidized state torise within the riser 16 and contact the feedstock as described above.Often times, the fluidizing gas is steam. In addition to fluidizing thecatalyst, the steam reduces the partial pressure of the hydrocarbons inthe riser 16, and helps drive the catalyzed reactions towards desiredproducts (as opposed to undesired byproducts).

In conventional FCC units, a control valve is used to lower the pressureof the steam in the conduit 58 prior to it being passed into the FCCunit 10. The present invention utilizes a turbine 60 in an isentropicexpansion to lower the pressure of the steam in conduit 58 prior topassing the steam into the FCC unit 10 which would result in a lowerenergy content steam versus that controlled by an adiabatic processcontrol valve. An exemplary turbine 60 is shown in FIG. 2.

Turning to FIG. 2, the turbine 60 includes a turbine wheel 62 withblades 64 configured to transfer, or transmit, rotational movement,created by the flow of the steam passed through the turbine wheel 62, toan electrical generator 66. The electrical generator 66 generallyincludes a first winding 68, in communication with the turbine wheel 62and a second winding 70 surrounding the first winding 68. As is known,the rotation of the first winding 68 relative to the second winding 70will generate an electrical current. Although not depicted as such, theelectrical generator 66 could include a permanent magnet instead of oneof the windings, 68, 70. Such electrical generators are known in theart.

Additionally, the turbine 60 may include a processor 72 configured tomeasure an amount of electricity generated by the turbine 60 and atransmitter 74 configured to transmit information associated with theamount of electricity generated by the turbine 60 to a computer 76 at acontrol center 78. The specific configuration of the turbine 60 is notessential to the practicing of the present invention provided that theturbine 60 allows for the desired pressure reduction and conversion ofenergy from the pressure reduction to electricity. Exemplary turbinesand further details are described in U.S. Pat. Nos. 4,625,125,4,694,189, 4,754,156 and 9,203,969, all of which are incorporated hereinby reference.

Accordingly, in some embodiments, the process according to the presentinvention comprises directing a portion of a gaseous process streamthrough one or more variable-resistance turbines to control the flowrateof the gas process stream and, optionally, generate electric powertherefrom; controlling a pressure and temperature of the gaseous processstream so that the gas exiting the power-recovery turbine remains in thegas phase; and measuring the flowrate or controlling the flowrate orboth using a variable nozzle turbine, inlet variable guide vanes, ordirect coupled variable electric load, to name a few, to vary theresistance to flow through the turbine. Again, the resistance torotation of the variable-resistance turbine can be varied by an externalvariable load electric circuit which is in a magnetic field from amagnet(s) that is rotating on the turbine. As more load is put on thecircuit, there is more resistance to rotation on the turbine. This inturn imparts more pressure drop across the turbine and slows the processstream flow. An algorithm in the device can also calculate the actualflow through the device by measuring the turbine RPMs and the load onthe circuit. The resistance to rotation flow can also be varied byvariable position inlet guide vanes. In some embodiments, the power willbe generated via power-recovery turbines with variable resistance toflow made possible by either guide vanes or variable load on theelectrical power generation circuit. An algorithm to calculate actualflow using the guide vanes position, power output and RPMs can be used.

Thus, the steam from conduit 58 will enter the turbine 60 at an inletand rotate the turbine wheel 62, thereby reducing the pressure andtemperature of the steam and extracting energy from the steam. The lowerpressure steam 59, taken from the outlet of the turbine 60, is injectedinto the riser 16 and reduces a partial pressure of a hydrocarbon vaporin the riser 16. The desired temperature of the steam at the outlet ofthe turbine 60 is preferably within 15 degrees C. of the dew point ofthe reduced pressure steam. It is also contemplated that a turbine 60 isutilized in place of control valves in association with the nozzles 19and/or with the line 40 for the stripping steam.

Turning to FIG. 3, it is also contemplated that a turbine is used inassociation with a quench stream, for example in a hydroprocessingreactor 100. As used herein, the term “hydroprocessing” can refer toprocessing one or more hydrocarbons in the presence of hydrogen, and caninclude hydrotreating and/or hydrocracking. As used herein, the term“hydrocracking” can refer to a process breaking or cracking bonds of atleast one long-chain hydrocarbon in the presence of hydrogen and atleast one catalyst into lower molecular weight hydrocarbons. As usedherein, the term “hydrotreating” can refer to a process includingcontacting a hydrocarbon feedstock with hydrogen gas in the presence ofone or more suitable catalysts for the removal of heteroatoms, such assulfur, nitrogen and metals from a hydrocarbon feedstock. Inhydrotreating, hydrocarbons with double and triple bonds may besaturated, and aromatics may also be saturated, as some hydrotreatingprocesses are specifically designed to saturate aromatics.

As depicted in FIG. 3, a hydroprocessing reactor 100 that is used inaccordance with the present invention is a multi-fixed bed vessel 101which, as is known, comprises multiple catalyst beds 102, 104, 106, 108that are separated from each other by pre-bed spaces 112, 114, 116 (alsoreferred to as quench zones. In an exemplary embodiment, each of thecatalyst beds 102, 104, 106, 108 contain a hydrotreating catalyst.Hydrotreating catalysts are well known and typically comprise molybdenum(Mo), tungsten (W), cobalt (Co), and/or nickel (Ni) on a supportcomprised of y-alumina. The particular type of hydrotreating catalyst isnot necessary for the understanding or practicing of the presentinvention.

As illustrated, a feed stream 118 is introduced to the hydroprocessingreactor 100. While the feed stream 118 is depicted as being introducedat the top of the vessel 101, it is contemplated that the feed stream118 is split and injected into the hydroprocessing reactor 100 atmultiple positions, such as the pre-bed spaces 112, 114, 116.

A hydrogen-containing stream 120 is also split in a plurality of streamsinto hydrogen rich streams 122, 124, 126, 128. Preferably, thehydrogen-containing stream 120 is a H₂-rich stream. As used herein, theterm “rich” means an amount generally of at least 50%, and preferably70%, by volume, of a compound or class of compounds in a stream. Thehydrogen-containing stream 120 may contain recycle hydrogen from thehydroprocessing reactor 100, make-up hydrogen, or a combination ofrecycle hydrogen and make-up hydrogen.

A first hydrogen rich stream 122 is combined with the feed stream 118(before or after injection into the vessel 101). The remaining hydrogenrich streams 124, 126, 128 are used as quench streams 130, 132, 134 andinjected into the pre-bed spaces 112, 114, 116 of the hydroprocessingreactor 100. In order to reduce the pressure of the quench streams 130,132, 134, turbines 60 a, 60 b, 60 c are used. These turbines 60 a, 60 b,60 c are, for example, the turbine 60 shown in FIG. 2. The turbines 60a, 60 b, 60 c may each be in communication with a temperature sensor 136configured to measure a temperature of one of the pre-bed spaces 112,114, 116 and relay the temperature to the turbines 60 a, 60 b, 60 c toadjust the flow of the respective quench streams 130, 132, 134.

Thus, the hydrogen rich streams 124, 126, 128 will enter each of theturbines 60 a, 60 b, 60 c and rotate turbine wheels therein (see, FIG.2), thereby reducing the pressure and temperature of the hydrogen richstreams 124, 126, 128 and extracting energy from the hydrogen richstreams 124, 126, 128. The lower pressure and temperature quench streams130, 132, 134 are injected into pre-bed spaces 112, 114, 116 of thereactor 100 and to control the temperature of the catalyst beds 104,106, 108 within the reactor 100.

In both the FCC unit 10 and the hydroprocessing reactor 100, the flowrate of the stream coming from the turbine 60 can be adjusted to changea process condition of the FCC unit 10 and the hydroprocessing reactor100. For example, the flow rate of the steam in the riser 16 is adjustedto allow for a change in the hydrocarbon partial pressure within theriser 16 and the catalyst circulation rate. Similarly, the flow rate ofthe quench streams 130, 132, 134 may be adjusted to change thetemperature of the catalyst beds 104, 106, 108 within the reactor 100.Accordingly, in changing these process conditions, it is contemplatedthat the changes are “slow control” in which the desired change occursat a relatively slow pace.

For example, with respect to the hydrotreating reactor 100, it iscontemplated that a response time to reach half way (i.e., 50% of adifference) between a new (or target) temperature within thehydrotreating reactor 100 and an original (or starting) temperaturewithin the hydrotreating reactor 100, when the new (or target)temperature differs from the original (or stating) temperature by atleast 10%, is at least one second, or even greater, for example, tenseconds. In other words, when the new temperature of the reactor differsfrom the current temperature within the reactor, the turbine provides aprocess that takes at least one second, at least ten seconds, at leastone minute, at least ten minutes, or an hour or more, for half of thechange to completed.

Similarly, with respect to the FCC unit 10, it is contemplated that theresponse time to reach half way (i.e., 50% of a difference) between anew (or target) hydrocarbon partial pressure within the FCC unit 10 andan original (or stating) hydrocarbon partial pressure within the FCCunit 10, when the new (or target) hydrocarbon partial pressure differsfrom the original (or stating) hydrocarbon partial pressure by at least10%, is also at least one second, at least ten seconds, at least oneminute, at least ten minutes, or an hour or more. One of ordinary skillin the art will be able to determine the process conditions and responsetime for the dynamic processes associated with the present invention.

Thus, if slow control response of the turbine is an issue then the useof the turbine is limited to slow responding or “loose” control pointapplications. A slow responding application is contemplated to have aresponse time to reach half way (i.e., 50% of a difference) between anew (or target) steady state condition (e.g., temperature, pressure,flow rate) from an original (or starting) steady state condition whenthe new (or target) condition differs from the original (or stating)condition of at least 10%, is of at least one second, or even greater,for example, ten seconds, at least one minute, at least ten minutes, oran hour or more, for half of the change to completed.

It is further contemplated that the chemical processing units used inthe present processes, such as the FCC unit 10 or the hydrotreatingreactor 100, utilizes a process control system.

The process control system described in connection with the embodimentsdisclosed herein may be implemented or performed on the computer with ageneral purpose processor, a digital signal processor (DSP), anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA) or other programmable logic device, discrete gate ortransistor logic, discrete hardware components, or any combinationthereof designed to perform the functions described herein. Ageneral-purpose processor may be a microprocessor, or, the processor maybe any conventional processor, controller, microcontroller, or statemachine. A processor may also be a combination of computing devices,e.g., a combination of a DSP and a microprocessor, two or moremicroprocessors, or any other combination of the foregoing.

The steps of the processes associated with the process control systemmay be embodied in an algorithm contained directly in hardware, in asoftware module executed by a 5 processor, or in a combination of thetwo. A software module may reside in RAM memory, flash memory, ROMmemory, EPROM memory, EEPROM memory, registers, hard disk, a removabledisk, a CD-ROM, or any other form of storage medium known in the art. Anexemplary storage medium is in communication with the processor readinginformation from, and writing information to, the storage medium. Thisincludes the storage medium being integral to or with the processor. Theprocessor and the storage medium may reside in an ASIC. The ASIC mayreside in a user terminal. Alternatively, the processor and the storagemedium may reside as discrete components in a user terminal Thesedevices are merely intended to be exemplary, non-limiting examples of acomputer readable storage medium. The processor and storage medium ormemory are also typically in communication with hardware (e.g., ports,interfaces, antennas, amplifiers, signal processors, etc.) that allowfor wired or wireless communication between different components,computers processors, or the like, such as between the input channel, aprocessor of the control logic, the output channels within the controlsystem and the operator station in the control center.

In communication relative to computers and processors refers to theability to transmit and receive information or data. The transmission ofthe data or information can be a wireless transmission (for example byWi-Fi or Bluetooth) or a wired transmission (for example using anEthernet RJ45 cable or an USB cable). For a wireless transmission, awireless transceiver (for example a Wi-Fi transceiver) is incommunication with each processor or computer. The transmission can beperformed automatically, at the request of the computers, in response toa request from a computer, or in other ways. Data can be pushed, pulled,fetched, etc., in any combination, or transmitted and received in anyother manner

According to the present invention, therefore, it is contemplated thatthe process control system receives information relative to an amount ofelectricity generated by the turbines 60. It is contemplated that theturbine determines the amount of electricity it has generated, oralternatively, the process control system receiving the informationdetermines the amount of electricity that has been generated. In eitherconfiguration, the amount of the electricity generated by the turbines60 is displayed on at least one display screen 80 (for example incommunication with the computer 76 in the control center 78). If theprocessing unit comprises a plurality of turbines 60, it is furthercontemplated that the processing control system receives informationassociated with the amount of electricity generated by each of theturbines 60. The processing control system determines a total powergenerated based upon the information associated with the each of theturbines 60 and displays that the total power generated. The total powergenerated may be displayed instead of or in conjunction with the displayof the power generated by individual turbines 60.

As discussed above, the recovery of the electricity is based upon theneed to remove energy form the streams that has already been added tothe streams in the processing units. Thus, it is contemplated that theprocesses according to the present invention provide for the variousprocess conditions associated with the processing units to be adjustedinto order to lower the energy added to the steam initially. It iscontemplated that the process control system receives informationassociated with the throughput of the processing unit, and determines atarget power generated value for the turbines 60, since the electricityrepresents energy that is typically added to the overall processingunit. The determination of the target power generated value may be donewhen the electricity is at or near a predetermined level. Thus, theprocess control system will analyze one or more changes to the variousprocess conditions associated with the processing unit to lower theamount of energy recovered by the turbines 60. Preferably, the processconditions are adjusted without adjusting the throughput of theprocessing unit. This allows for the processing unit to have the sameoutput, but with a lower operating input. The process control softwaremay calculate and display the difference between the target powergenerated value and the total power generated on the at least onedisplay screen 80.

EXAMPLES

In simulated examples of the present invention, it was determined thatby using a turbine 60 instead of a control valve, the quench temperaturefor a hydroprocessing reactor could be reduced by 5-10° C. It isbelieved that this could reduce the hydrogen demand requirements for thequench stream by up to 5% or alternatively debottleneck the hydrocarbonfeed rate by a similar amount. Another option would be to use thisreduction in the quench hydrogen demand to shift hydrogen to the reactorinlet. Additionally, or alternatively, the reduction in the quenchhydrogen demand reduces the power consumption of the recycle gascompressor used in association the hydrogen containing gas stream. Foran FCC unit, it was determined that by using a turbine 60 instead of acontrol valve, the catalyst to oil (feedstock) ratio could be increasedwith an increase in yield (as opposed to increase in undesiredbyproducts) which increases the profitability of the FCC unit or allowfor more feed while maintaining a constant catalyst to oil ratio.

Thus, not only does the present invention recover energy that istypically lost, the present invention provides advantages to theunderlying process conditions of the processing unit.

It should be appreciated and understood by those of ordinary skill inthe art that various other components such as valves, pumps, filters,coolers, etc. were not shown in the drawings as it is believed that thespecifics of same are well within the knowledge of those of ordinaryskill in the art and a description of same is not necessary forpracticing or understanding the embodiments of the present invention.

Specific Embodiments

While the following is described in conjunction with specificembodiments, it will be understood that this description is intended toillustrate and not limit the scope of the preceding description and theappended claims.

A first embodiment of the invention is a process for reducing pressureof a vapor stream used for reducing a temperature, heat load, orhydrocarbon partial pressure in a reactor, the process comprisingreducing a pressure of a vapor stream with a turbine to provide a lowerpressure vapor stream; rotating a turbine wheel within the turbine,injecting the lower pressure vapor stream into a reactor and reducing atemperature in the reactor or reducing a partial pressure of ahydrocarbon vapor in the reactor. An embodiment of the invention is one,any or all of prior embodiments in this paragraph up through the firstembodiment in this paragraph further comprising increasing the feed rateto the reactor by relaxing a high temperature bottleneck by extractingenergy from the vapor stream. An embodiment of the invention is one, anyor all of prior embodiments in this paragraph up through the firstembodiment in this paragraph wherein the turbine wheel is configured totransmit rotational movement to an electrical generator, and the processfurther comprising generating electricity with the turbine. Anembodiment of the invention is one, any or all of prior embodiments inthis paragraph up through the first embodiment in this paragraph furthercomprising receiving information from the turbine relative to an amountof electricity generated by the turbine; and, displaying the amount ofelectricity generated by the turbine on at least one display screen. Anembodiment of the invention is one, any or all of prior embodiments inthis paragraph up through the first embodiment in this paragraph furthercomprising maintaining a throughput of the reactor while adjusting atleast one process parameter of the reactor. An embodiment of theinvention is one, any or all of prior embodiments in this paragraph upthrough the first embodiment in this paragraph, wherein the reactorcomprises a plurality of turbines each configured to generateelectricity, and wherein the process comprises determining a total powergenerated based upon the amount of electricity generated by theturbines; and, displaying the total power generated value on the atleast one display screen. An embodiment of the invention is one, any orall of prior embodiments in this paragraph up through the firstembodiment in this paragraph wherein the reactor comprises an FCCreactor, and wherein the vapor stream comprises a steam stream. Anembodiment of the invention is one, any or all of prior embodiments inthis paragraph up through the first embodiment in this paragraph whereinthe reactor comprises a hydroprocessing reactor, and wherein the vaporstream comprises a hydrogen stream.

A second embodiment of the invention is a process for reducing pressureof a vapor stream used for adjusting a partial pressure of a hydrocarbonvapor, the process comprising providing a vapor stream comprising steam;passing the vapor stream through a turbine, the turbine comprising aturbine wheel within the turbine; and, reducing a partial pressure of ahydrocarbon vapor by mixing the reduced pressure vapor stream with thehydrocarbon vapor. An embodiment of the invention is one, any or all ofprior embodiments in this paragraph up through the second embodiment inthis paragraph, wherein the reduced pressure vapor stream is injectedinto an FCC reactor to reduce the partial pressure of the hydrocarbonvapor in the FCC reactor. An embodiment of the invention is one, any orall of prior embodiments in this paragraph up through the secondembodiment in this paragraph further comprising recovering electricitygenerated with the turbine. An embodiment of the invention is one, anyor all of prior embodiments in this paragraph up through the secondembodiment in this paragraph further comprising adjusting one or moreprocess conditions for the FCC reactor based upon a cooling dutyprovided by the turbine. An embodiment of the invention is one, any orall of prior embodiments in this paragraph up through the secondembodiment in this paragraph, wherein the outlet temperature is within15 degrees C. of the dew point of the reduced pressure vapor stream. Anembodiment of the invention is one, any or all of prior embodiments inthis paragraph up through the second embodiment in this paragraph,wherein a response time to reach 50% of a difference between the partialpressure and an original partial pressure, when the partial pressurevaries from the original partial pressure by at least 10%, is at leastone second. An embodiment of the invention is one, any or all of priorembodiments in this paragraph up through the second embodiment in thisparagraph, wherein a change response time to reach 50% of a differencebetween the partial pressure and an original partial pressure, when thepartial pressure varies from the original partial pressure by at least10%, is at least ten seconds.

A third embodiment of the invention is a process for reducing pressureof a vapor stream used as a quench stream, the process comprisingproviding a vapor stream comprising hydrogen; passing the vapor streamthrough a turbine, the turbine comprising a turbine wheel within theturbine; recovering a reduced pressure vapor stream from the turbine;and, controlling a temperature within a reactor with the reducedpressure vapor stream from the turbine. An embodiment of the inventionis one, any or all of prior embodiments in this paragraph up through thethird embodiment in this paragraph wherein the reactor comprises ahydroprocessing reactor. An embodiment of the invention is one, any orall of prior embodiments in this paragraph up through the thirdembodiment in this paragraph further comprising determining a coolingduty of the turbine; and, adjusting one or more process conditions forthe hydroprocessing reactor based upon the cooling duty of the turbine.An embodiment of the invention is one, any or all of prior embodimentsin this paragraph up through the third embodiment in this paragraphfurther comprising adjusting a process condition of the vapor stream toachieve a desired hydroprocessing reactor temperature. An embodiment ofthe invention is one, any or all of prior embodiments in this paragraphup through the third embodiment in this paragraph, wherein the reducedpressure vapor stream is injected into the reactor to adjust atemperature of at least one catalyst bed. An embodiment of the inventionis one, any or all of prior embodiments in this paragraph up through thethird embodiment in this paragraph, wherein a response time to reach 50%of a difference between the temperature within the reactor and anoriginal temperature within the reactor, when the temperature within thereactor varies from the original temperature within the reactor by atleast 10%, is at least one second. An embodiment of the invention isone, any or all of prior embodiments in this paragraph up through thethird embodiment in this paragraph, wherein a response time to reach 50%of a difference between the temperature within the reactor and anoriginal temperature within the reactor, when the temperature within thereactor varies from the original temperature within the reactor by atleast 10%, is at least ten seconds. An embodiment of the invention isone, any or all of prior embodiments in this paragraph up through thethird embodiment in this paragraph further comprising recoveringelectricity generated with the turbine.

Without further elaboration, it is believed that using the precedingdescription that one skilled in the art can utilize the presentinvention to its fullest extent and easily ascertain the essentialcharacteristics of this invention, without departing from the spirit andscope thereof, to make various changes and modifications of theinvention and to adapt it to various usages and conditions. Thepreceding preferred specific embodiments are, therefore, to be construedas merely illustrative, and not limiting the remainder of the disclosurein any way whatsoever, and that it is intended to cover variousmodifications and equivalent arrangements included within the scope ofthe appended claims.

In the foregoing, all temperatures are set forth in degrees Celsius and,all parts and percentages are by weight, unless otherwise indicated.

While at least one exemplary embodiment has been presented in theforegoing detailed description of the invention, it should beappreciated that a vast number of variations exist. It should also beappreciated that the exemplary embodiment or exemplary embodiments areonly examples, and are not intended to limit the scope, applicability,or configuration of the invention in any way. Rather, the foregoingdetailed description will provide those skilled in the art with aconvenient road map for implementing an exemplary embodiment of theinvention, it being understood that various changes may be made in thefunction and arrangement of elements described in an exemplaryembodiment without departing from the scope of the invention as setforth in the appended claims and their legal equivalents.

1. A process for reducing pressure of a vapor stream used for reducing atemperature, heat load, or hydrocarbon partial pressure in a reactor,the process comprising: reducing a pressure of a vapor stream with aturbine to provide a lower pressure vapor stream; rotating a turbinewheel within the turbine, injecting the lower pressure vapor stream intoa reactor and reducing a temperature in the reactor or reducing apartial pressure of a hydrocarbon vapor in the reactor.
 2. The processof claim 1 further comprising increasing the feed rate to the reactor byrelaxing a high temperature bottleneck by extracting energy from thevapor stream.
 3. The process of claim 1 wherein the turbine wheel isconfigured to transmit rotational movement to an electrical generator,and the process further comprising: generating electricity with theturbine.
 4. The process of claim 3 further comprising: receivinginformation from the turbine relative to an amount of electricitygenerated by the turbine; and, displaying the amount of electricitygenerated by the turbine on at least one display screen.
 5. The processof claim 4 further comprising: maintaining a throughput of the reactorwhile adjusting at least one process parameter of the reactor.
 6. Theprocess of claim 4, wherein the reactor comprises a plurality ofturbines each configured to generate electricity, and wherein theprocess comprises: determining a total power generated based upon theamount of electricity generated by the turbines; and, displaying thetotal power generated value on the at least one display screen.
 7. Theprocess of claim 1 wherein the reactor comprises an FCC reactor, andwherein the vapor stream comprises a steam stream.
 8. The process ofclaim 1 wherein the reactor comprises a hydroprocessing reactor, andwherein the vapor stream comprises a hydrogen stream.
 9. A process forreducing pressure of a vapor stream used for adjusting a partialpressure of a hydrocarbon vapor, the process comprising: providing avapor stream comprising steam; passing the vapor stream through aturbine, the turbine comprising a turbine wheel within the turbine; and,reducing a partial pressure of a hydrocarbon vapor by mixing the reducedpressure vapor stream with the hydrocarbon vapor.
 10. The process ofclaim 9, wherein the reduced pressure vapor stream is injected into anFCC reactor to reduce the partial pressure of the hydrocarbon vapor inthe FCC reactor.
 11. The process of claim 10 further comprising:recovering electricity generated with the turbine.
 12. The process ofclaim 11 further comprising: adjusting one or more process conditionsfor the FCC reactor based upon a cooling duty provided by the turbine.13. The process of claim 12, wherein the outlet temperature is within 15C of the dew point of the reduced pressure vapor stream.
 14. The processof claim 10, wherein a response time of at least one steady stateprocess condition to a new steady state process condition of at least10% difference is at least one second to reach 50% of the differencebetween the at least one steady state process condition and the newsteady state process condition after modulating the resistance of theturbine.
 15. The process of claim 10, wherein a response time of atleast one steady state process condition to a new steady state processcondition of at least 10% difference is at least ten seconds to reach50% of the difference between the at least one steady state processcondition and the new steady state process condition after modulatingthe resistance of the turbine.
 16. A process for reducing pressure of avapor stream used as a quench stream, the process comprising: providinga vapor stream comprising hydrogen; passing the vapor stream through aturbine, the turbine comprising a turbine wheel within the turbine;recovering a reduced pressure vapor stream from the turbine; and,controlling a temperature within a reactor with the reduced pressurevapor stream from the turbine.
 17. The process of claim 16 wherein thereactor comprises a hydroprocessing reactor.
 18. The process of claim 16further comprising: determining a cooling duty of the turbine; and,adjusting one or more process conditions for the hydroprocessing reactorbased upon the cooling duty of the turbine.
 19. The process of claim 18further comprising: adjusting a process condition of the vapor stream toachieve a desired hydroprocessing reactor temperature.
 20. The processof claim 16, wherein the reduced pressure vapor stream is injected intothe reactor to adjust a temperature of at least one catalyst bed. 21.The process of claim 16, wherein a response time to reach 50% of adifference between the temperature within the reactor and an originaltemperature within the reactor, when the temperature within the reactorvaries from the original temperature within the reactor by at least 10%,is at least one second.
 22. The process of claim 16, wherein a responsetime to reach 50% of a difference between the temperature within thereactor and an original temperature within the reactor, when thetemperature within the reactor varies from the original temperaturewithin the reactor by at least 10%, is at least ten seconds.
 23. Theprocess of claim 16 further comprising: recovering electricity generatedwith the turbine.